Conventionally, in a linear synchronous motor in which a movable element is linearly moved by a field generated by a permanent magnet and a moving magnetic field generated by an armature, the position and the moving speed of the movable element is controlled by using a position sensor, a speed sensor, magnetic polar sensor and the like.
On the other hand, as a control method in which a linear synchronous motor is driven without using a sensor, a sensor-less vector control technology is generally utilized (for example, refer to Patent Publication 1). In the sensor-less vector control technology, there is generally adopted a method of estimating a position and a moving speed of a movable element by using induced electromotive force induced to an armature by rotation of a linear synchronous motor.